The present invention relates to security revolving doors, and in particular, a revolving door with metal detection security which may also have additional security. Security revolving doors are known. For example, in U.S. Pat. No. RE 33,407, issued to the present inventor, a revolving door has security triggered by a mat which detects tailgating (an unauthorized person entering the revolving door in a compartment other than the one entered by an authorized person), piggybacking (two persons in the same compartment), and pass back (an authorized user passing his/her card back to an unauthorized user).
The present inventor also holds U.S. Pat. Nos. 5,012,455 and 5,097,454 using ultrasonic sensors to perform anti-pass back and anti-tailgating functions, and U.S. Pat. No. 5,201,906 for ultrasonic sensors for security doors with anti-pass back, anti-tailgating and anti-piggybacking.
Metal detectors are also known. When they are used in a building having a revolving door, the metal detector is set up at a separate station where there is a guard. This is typically encountered in a courthouse or other government, building.
What is needed, is a metal detector in combination with a revolving door where the revolving door can perform the security function in response to metal detection, yet the door may still function and not itself be detected by the metal detector.
In one embodiment, the present invention provides a revolving door with a detection function. A metal detector will detect a predetermined sufficient amount of metal. The door will not allow a user with such a sufficient amount of metal to pass through. One also cannot pass a gun or other metal object through the revolving door. The door itself is modified by having its metal glass wing holding supports extend only for a portion of the radius of the door wing.
In another embodiment, a security revolving door such as in the aforementioned U.S. patents is combined with metal detection security.
In a further embodiment, the door may be made with the metal detector adjacent the door by modifying the door to eliminate metal on the portion of the door wings that will pass through the detector and any other metal on the door that may be a problem for the detector, or the metal detector may be spaced from the door by a pair of walls or enclosure so that the door structure need not be modified and to ensure that a user cannot slip between the detector and the door.